1. Field of the Invention
The present invention relates to the technology field of OLEDs, and more particularly to an electro-fluorescent emitter for ultra-violet OLED.
2. Description of the Prior Art
Ultraviolet light, invisible to the naked eye, is one component of the natural light (i.e., sunlight). As the spectrum diagram of sunlight presented by FIG. 1 shows, the wavelength of ultraviolet light ranges between 100 nm and 400 nm. Moreover, the ultraviolet light can be further divided to Vacuum UV (VUV), Far-UV (UVC), Mid-UV (UVB), and Near-UV (UVA) with the wavelength difference of UV light. Nowadays, UV light is well known can be applied to the following technique fields: biological and chemical sensors, leakage detection in automobiles, high density information storage devices, water treatment for germicidal protection, crack detection in airplanes, forensic investigations, sanitation and sterilization, laboratory researches, food industries, and fraud detection.
Conventionally, UV light can be produced or emitted from a xenon arc lamp, an incandescent lamp, a fluorescent lamp, a mercury vapor lamp, a laser diode, or a light emitting diode (LED); that means all the xenon arc lamp, the incandescent lamp, the fluorescent lamp, the mercury vapor lamp, the laser diode, and the light emitting diode (LED) can be used as a UV light source. Please refer to FIG. 2 and FIG. 3, which illustrate the emission spectrum diagrams of two UV lights emitted by a laser diode and an LED, respectively. As FIG. 2 shows, the UV light emitted by the laser diode obviously includes a visible light component. Similarly, the UV light emitted by the LED apparently includes a visible light component as shown in FIG. 3. Moreover, according to researches, it can be known that the UV light emitted by the xenon arc lamp, the incandescent lamp, the fluorescent lamp, or the mercury vapor lamp also includes the visible light component and/or an infrared ray component.
So that, the emission spectrum diagrams have proved that the UV light emitted by the conventional UV light source is not a pure UV light. So that, it can reasonably assume that such impure UV light cannot provide a best and most-effective assistance in the technique fields of water treatment for germicidal protection, forensic investigations, sanitation and sterilization, food industries, and fraud detection; more negatively and seriously, such impure UV light may provide an adverse effect.
Organic light emitting device (OLED), a novel light device, is well known including the advantages of high brightness, fast response time, light weight, compactness, true color, no difference in viewing angles, capable of light by plane, and low power consumption. However, there is no UV OLED being proposed or fabricated up to now.
Accordingly, in view of there is still no UV OLED being proposed or fabricated, the inventor of the present application has made great efforts to make inventive research thereon and eventually provided an electro-fluorescent emitter for ultra-violet OLED.